Bag filling machine



May 19, 1964 E. M. LAU

BAG-FILLING MACHINE 3 Sheets-Sheet 1 Filed 1962 May 19, 1964 E M. LAUBAG-FILLING MACHINE Filed Feb. 5, 1962 3 Sheets-Sheet 2 f7? #92? for.Era/1'72 J17. Zea

May 19, 1964 E. M. LAU 3,133,608

BAG-FILLING MACHINE Filed Feb. 5, 1962 3 Sheets-Sheet 3 parts of thefeeding mechanism.

United States Patent 3,133,608 BAG FILLING MACHINE Erwin M. Lau, Bolton,111., assignor to Black Products Co., Chicago, Ill., a corporation ofIllinois Filed Feb. 5, 1962, Ser. No. 171,200 8 Claims. (Cl. 177-118)This inventionrelates to improvements in bag filling machines of theautomatic cutoff type. i V

In machines of this type, the bag is suspended from the filling spout.The filling spout is mounted for vertical movement and it bears on thebeam of the scale mechanism. When a predetermined amount of material hasbeen fed into the bag, the movement of the beam cuts off the fillingoperation.

, An object of this invention is to provide a bag filling machine inwhich the beam axis is parallel to the spout axis so that the positionof the bag on the spout will not vary the length of the lever arm, andhence affect the accuracy of the scale mechanism.

Another object is to provide a spout assembly in the form of a suspendedelement, thus reducing the number of bearing points required andproviding a siniplifiedconstruction without sacrifice of sensitivity.

A further object is to provide, in a parallel beam axis type of machine,a beam and spout assembly construction which does not interfere with thelocation of the various The present application is acontinuation-in-part of my copending application, Serial No. 801,143filed March 23, 1959 now Patent No. 3,062,307, granted November 6, 1962.I

In my aforesaid copending applicatiomthe suspended spout assembly wasstabilized against backward swinging movement by a strut which reacted von the supporting framework. The strut develops a horizontal force, com

ponent which may result in a climbing of'the spout assembly, and thisclimbing affects the beam in a manner which detracts from the accuracyof the weighing operation. I

3,133,608 Patented May 19, 1964 FIG. 3 is a fragmentary of FIG. 1; i

FIG. 4 is a front elevation of the scale mechanism divorced from theremainder of the machine;

FIG. 5 is a side elevation of FIG. 4;

FIG. 6 is a rear elevation of FIG. 4, but with the, I

ing framework 19. Mounted above the bed plate are feeding mechanismdesignated generally by the reference numeral 11, and scale mechanismshown in FIGS. 47

A which includes a beam 25, and a suspended spout as- A further objectof my invention is to provide a stabilized arrangement which eliminatesthe use of the strut.

The strut arrangement is not entirely satisfactory for another reason;in certain filling operations, particularly those involving powderymaterials, the d-rippage from the spout will settle on and diminish thesensitivity of the bearing points of the strut. Furthermore, where thestrut is located close to the floor, the drippa ge will pile up on thefloor and. will clog the bearing points or interfere with the freemovement of the strut, or both.

It is another object of this invention to provide a scale mechanism fora parallel beam axis type of machine in I which all of the bearingpoints are located in an elevated According to my invention, the spoutassembly is sus pended from the beam at two spaced points. In theparposition. i

ticular embodiment shown, the spout assembly is in the form of a cradleso that it does not interfere with the location of the various parts ofthe feeding mechanism. Since thespout assembly is supported at twopoints it will be stable provided that the center of gravity of thespout assembly system, including theweight of the bag contents, islocated between the two points of suspension.

Other objects, features and advantages of my invention will becomeapparent as the description proceeds.

' With reference now to the drawings in which like reference numeralsdesignate like parts: I

FIG. 1 is a side elevation of a preferred embodiment of my invention;

FIG. 2 is a sectional detail showing the bearing point construction;

sembly 34. I

The feeding mechanism 11 shown herein by way of example comprises aconditioningchamber 12 having as its bottom wall a diffusing pad 13. Aflexible flanged tube 14, such as a rubber tube, extends forwardly froman opening in the'front wall of the conditioning chamber 12 andcommunicates with the rear end of a spout 15 on which the bag is to besuspended. The flanged tube 14 is supported at an intermedate point by avertical plate 17 whiohismounted on the bed plate 10.

Material is caused to flow from the conditioning chamber 12 through theflanged tube 14 and into a bag 20 when the diffuser pad 13 is energizedby means of an air supply 18. Cutoff means to discontinue the feedingoperation are provided in the form of a pinch valve 16 for the tube 14.Thefeeding mechanism is described in,

greater detail in'my Patent No. 2,936,994, granted .May 17, 1960, towhich referenceis hereby made.

- Scale mechanism is provided to actuate the cutoff means when theweight of the bag contents reaches a predetermined amount. The scalemechanism comprises a beam 25 which is mounted on fulcrum means 21 insuch a manner that the fulcrum axis of the beam is parallel to the axisof the spout 15.

The fulcrum means 21 is in the form of a U-shaped structure, shown inFIG. 11, which is disposed adjacent to a flange of thebed'plate 10, asshown in FIG. 3, and

'Which maybe suitably secured thereto and to the cross members of thesupporting framework 19. The fulcrum meansis provided with fulcrumpoints in the form of conical bearing points 22 which, as shown in FIG.2, are separately formed members of hardened steel which are 'mountedonthe fulcrum member 21 by means of a shank 23. i

The beam 25, as shown in FIG. 10, comprises front and rear invertedU-shaped members 26 and 27 which are connected by a longitudinallyextending side bar 28.

Hardened bearing pads 29 are set intoeach of the members 26 and 2'7, andthe construction is shown in FIG. 2. Each bearing pad 29 is providedwith a conical recess 3%) in which the bearing point 22 is received. Thebearing pad'29 is also provided with a shank 31 bymeans of V which itcan be accurately locatedagainst the shoulder of a oounterhore formed inthe members 26 and 27. The bearing point 22 may comprise a 60 cone, and

I the recess 30 may comprise a conical surface, the

radius of the point of the former being of an inch and the radius of theapex of the latter being of an inch. The parts 22 and 29 are preferablymade of hardsection taken along line 33 ened tool steel so that theywill provide a substantially frictionless and very sensitive bearingsurface.

The spout assembly 34 is suspended from the beam at two spaced points.As shown in H6. 9 the spout assembly 34 is a U-shaped member having twosupport lugs 35 and 36 in which conical bearing pads, similar to thebearing pads 29, are mounted for cooperation with bearing points 37 and38 which are mounted in the front and rear members 26 and 27 of the beam25.

The spout assembly 34 includes a mounting plate at which forms the frontleg thereof and which is provided, as shown in FIG. 9, with an'opening4h. The spout 15 is rigidly mounted in the opening so that it forms apart of and moves with the spout assembly. Thus the 'medialplane of thesuspended spout assembly 34 will tend to remain vertical during therocking of the beam 25, and the lever arm, which constitutes thehorizontal distance between the fulcrum points 22 and 37, will bemaintained constant at all times. According to this arrangement, thelocation of the bag 2%? upon the spout 15 will not affect the lever arm.

The spout assembly is so designed that the moment of the spout assembly34 with respect to the front bearing point 37 is greater than the momentof the bag 2b and contents, so as to stabilize the spout assemblyagainst backward tilting. To this end, it may be necessary to addcounterweights 42 to the rear portion of the spout assembly 34.

In some types of bag filling apparatus, it is customary to provide asaddle or platform to support the lower end of the bag 24), and in thisevent, saddle hanger rods 43 may be secured to the lower end of themounting plate for supporting such saddle.

The beam 25 is loaded by applying a balance weight 44 which is supportedfrom the beam by a bracket 45, the bracket and balance weight beingshown in FIG. 8. The beam 25, as shown in MG. 10, may be provided withone or more bearing points 46 for engaging the bracket 45, the latterbeing provided with conical bearing pads similar to the bearing pads 29.The moment of the balance weight 44 must be sufficient to offset notonly the weight of the bag contents, but also the weight of the spoutassembly 34, including any counterweights 4-2.

A microswitch Sil is mounted on a suitable bracket 51 (FIG. 1) so thatthe plunger thereof will be engaged by a portion of the beam 25. In thearrangement shown, the microswitch is a biased open microswitch, theplunger of which is engaged by the underside of the side bar 28. Whenthe weight of the bag contents exceeds the scale setting, then the beamwill be tripped, breaking a suitable control circuit which closes thecatch valve 16. Preferably, the air supply 18 to the diffuser pad mayalso be cut off at this time by the control circuit.

Suitable stop means may be provided to limit the throw of the beam. Asshown in FIG. 3, the stop means may be in the form of a yoke 52 which issuitably mounted on a bracket 57 and which engages the side bar 28.Screws 53 are preferably threaded into the yoke 52 to provide a fineadjustment, and a similar adjustment is desirably provided for themicroswitch in the form of a threaded pin 54 (FIG. 1) which engages theplunger of the microswitch do.

As shown in FIGS. 1 and 42m auxiliary scale beam 55 may be mounted onthe front member 26 of the beam 25. A weight as is slidably mounted onthe auxiliary scale beam 55. This provides a fine adjustment for thescale mechanism which is particularly useful in changing from one typeof bag to another. In other words, hundred pound bags will vary indimensions according to the type of material being packed, and thisvariation in dimensions is reflected in variation in weight which may befrom a few ounces up to a pound. According to this aspect of myinvention, the auxiliary scale beam 55 can be calibrated for differenttypes of bags with the result that in changing over from one material land bag type to another, it will not be necessary to provide a separatebalance weight for each type of bag.

The conical bearing point construction herein shown provides not only ahigh degree of sensitivity, but it also takes up horizontal forces ofconsiderable magnitude without impairment of accuracy. For instance, oneof the difiiculties encountered in the edge disk type of hearingdescribed in my aforesaid copending application is that this type ofbearing permits a longitudinal displacement of the beam which in turnincreases the clearance between the scale beam 25 and the plunger of themicroswitch 50. Any change in clearance reduces accuracy for the reasonthat it accelerates or retards the reaction interval, that is theinterval between initial movement of the scale beam and actuation of thecutoff valve 16. Also, longitudinal displacement destroys the alignmentof the pin 54 and the plunger of switch 50.

Longitudinal displacement can occur due to vibration of the beam 25 inthe longitudinal direction induced by operation of a bag settler,particularly one of the saddle type which is suspended from the hangerrods 43. Also, in the single point of suspension type of spout assembly,as pointed out in the aforesaid copending application, there is ahorizontal reaction force at the bearing point between the spoutassembly and the beam, and this will be transmitted to the beamresulting in longitudinal. displacement thereof unless taken up by thebearing points.

In FIG. 12, the spout assembly 34 is supported from the beam 25 only atone point, the bearing point 37, and is stabilized against backwardswinging movement by means of a strut 60 or other link which extendsbetween the lower end of the saddle hanger rods 43' and a part of theframework 19. FIG. 12 also shows the saddle or platform 61. Thearrangement is otherwise the same as described in connection with FIG.1.

To summarize the operation, which has heretofore been pointed out indetail in connection with the description of the various parts andsubassemblies, the beam 25 1S first loaded with a balance weight 44selected in accordance with the amount of material to be packed in thebag. Then the bag 20 is slipped over the spout l5 and the fillingoperation is initiated by causing the pinch yalve 16 to be opened and bysupplying air to the diffusing pad 13. At this time the side bar 28engages the lower arm of the yoke 52 as shown in FIG. 3. Then, when thedesired amount of material has been fed into the bag the beam 25 will betripped causing the beam to be rotated in the counterclockwise directionas viewed in FIG. 4 and operating the microswitch 50 to actuate thecutoff means 16. The flexibility of the tube 14 permits verticalmovement of the spout assembly 34 or 34' with respect to the feedingmechanism 11 without detracting from the accuracy or sensitivity of thescale mechanism.

When my invention is used with an auger type filling mechanism, a doubletube spout arrangement may be employed to permit free movement of thespout assembly, this arrangement being shown in my Patent No. 2,733,040,issuedlanua'ry 31, 1956.

It will be noted that both the beam 25 and the cradle 34 are shaped soas to avoid interference with the feeding mechanism which extends intothe space between the front and rear beam arms 26 and. 27. Thus, myarrangement may be used with various types of feeding mechan1sm, thefiuidizing type being shown herein for purposes of illustration only.

Although only preferred embodiments of this invention have been shownand described herein, it will be understood that various modificationsand changes may be made in the constructions shown without departingfrom the spirit of this invention as pointed out in the appended claims.

The subject matter of my aforesaid copending application, Serial No.801,143, is incorporated herein by reference, insofar as consistent withthe present disclosure,

and the present application forms a continuation-in-part thereof.

I claim:

l. A bag filling machinecomprising material feeding mechanism and scalemechanism for actuating the same, I

said scale mechanism including a beam having spaced front and rear beamarms and a longitudinal connecting member,

a spout assembly supported from said front and rear beam arms, andincluding a bag supporting spout communicating with said feedingmechanism,

means for mounting said beam on a fulcrum axis which is parallel to theaxisof said spout whereby the longitudinal position of a bag which issuspended from said spout will not affect the lever arm of the forceexerted by said bag upon said beam,

and means for connecting a balance weight to said beam at a pointrearwardly of said front beam arm,

the mass distribution of said spout assembly being such that the centerof gravity of the system comprising said spout assembly and the contentsof the bag supported thereby will be located between said front and rearbeam arms.

2. Abag filling machine comprising material feeding mechanism and scalemechanism,

said scale mechanism including a beam having spaced front andrear beamarms and a longitudinal connecting member,

a suspended spout assembly supported from said beam at two pointsofsuspension and including a bagsupporting spout which communicates withsaid feeding mechanism and which extends forwardly beyond said frontbeam arm,

fulcrum means for mounting said beam on a fulcrum axis whichis parallelto the axis of said spout whereby the longitudinal position of a bagwhich is suspended from said spout will not affect the lever arm of theforce exerted by said bag'upon said beam,

said feeding mechanism including cutoff means for discontinuing thefeeding operation, and

means actuated by the movement of said beam when the material fed intosaid bag reaches a predetermined weight for actuating said cutoff means,and

balance weight means connected to saidbeam at a point rearwardly of saidfront beam arm.

3. A bagfilling machine as claimed in claim 2 in which said two pointsof suspension are aligned substan tially parallel to. said fulcrum axis.

4. A bag filling machine as claimed in claim 2 in which said suspendedspout assembly is in the form'of a cradlewhich is supported from saidfront and rear beam arms.

5. bag filling machine as claimed in claim 2 in which'said suspendedspout assembly isin the form of a cradle, the alignment of said pointsof suspension being substantially parallel to said fulcrum axis, and themass distribution of said spout assembly being such that the center ofgravity of the system comprising said spout assembly and the contents'ofthe bag supported thereby Will'be located between said front and rearbeam arms in order to stabilize said spout assembly against back-' wardswinging movement.

'6. A bag filling machine as claimed in claim 5 which includes acounterweight mounted on said cradle.

8. In a bag filling machine which includes material feeding mechanismhaving cutoif means for discontinuing the feeding operation, and scalemechanism for actuating said cutoff means, said scale'mechanismincluding a beam having spaced front and rear beam arms and alongitudinal connecting member, and two'longitudinally' spaced fulcrummembers engaging said two beam arms for supporting said beam about alongitudinal fulcrum axis, the combination of aspout assembly suspendedfrom said beam on one side of said fulcrum axis, and a balance weightconnected to said beam on the opposite side of said fulcrum axis, saidspout assembly comprising a vertically hanging longitudinally disposedU-shaped member supported at its upper ends by said front and rear beamarmsand including a longitudinally disposed bag supporting spoutcommunicating with said feeding mechanism, and counterweight meansmounted on said spout assembly to prevent same from tipping forwardlydue to i the weight of the bag suspended from said spout.

1 References Cited in the file of this patent UNITED STATES PATENTS2,408,225 Peterson Sept. 24, 1946 2,866,484 Rose Dec. 30, 1958 2,937,863Hadley May 24, 1960' a FOREIGN PATENTS 634,199 Canada Jan. 9, 1962795,631 Great Britain s

1. A BAG FILLING MACHINE COMPRISING MATERIAL FEEDING MECHANISM AND SCALEMECHANISM FOR ACTUATING THE SAME, SAID SCALE MECHANISM INCLUDING A BEAMHAVING SPACED FRONT AND REAR BEAM ARMS AND A LONGITUDINAL CONNECTINGMEMBER, A SPOUT ASSEMBLY SUPPORTED FROM SAID FRONT AND REAR BEAM ARMS,AND INCLUDING A BAG SUPPORTING SPOUT COMMUNICATING WITH SAID FEEDINGMECHANISM,